Game Rules

1. The board and the checkers

Backgammon is a game for two players. Each player has 15 checkers of one colour — White (light) or Black (dark) — and the game is played with two dice and a doubling cube. The board has 24 narrow triangles called points, grouped into four quarters of six points. The bar runs down the middle and divides the board into two halves.

Each player numbers the points from their own side, from 1 to 24:

• points 1–6 are your home board;
• points 7–12 are your outer board;
• points 13–18 are your opponent's outer board;
• points 19–24 are your opponent's home board.

Your 1-point is your opponent's 24-point, your 2-point is their 23-point, and so on. You move your checkers from higher-numbered points to lower-numbered ones — out of your opponent's home board, round the board and into your own home board. Your opponent moves in the opposite direction.

Starting position. Each player starts with 2 checkers on their 24-point, 5 on their 13-point, 3 on their 8-point and 5 on their 6-point.

Object of the game. Bring all 15 of your checkers into your home board and then remove them from the board (bear them off). The first player to bear off all their checkers wins the game.

2. Starting a game

• To start the game, each player rolls one die. The player with the higher number moves first and plays the two numbers just rolled, one from each die. If both dice show the same number, both players roll again.
• After the first move the players take turns. On each turn you roll both dice and move your checkers.
• Every new game in a match starts with a new opening roll in the same way.

3. Moving the checkers

• The number on each die tells you how many points to move one checker. The two dice are two separate moves: you can move two different checkers, or one checker for both numbers. If one checker plays both numbers, the point where it stops after the first number must also be open.
• A checker can only land on an open point, which is any point not held by two or more of your opponent's checkers. There is no limit to how many of your own checkers can stand on one point.
• Doubles. If you roll doubles (the same number on both dice), you play that number four times. With 6-6, for example, you make four moves of six points, with any checkers you choose.
• You must use as much of the roll as you legally can. If you can play both numbers, you must play both. If you can play either number but not both, you must play the larger one. If you can play only one number, you must play it. If you cannot move at all, you lose your turn. With doubles, you play as many of the four moves as you can.

Example: with a roll of 5-3 you can move one checker 5 points and another 3 points. You can also move one checker 8 points, provided the point 3 or 5 points from its starting point is open.

4. Hitting and entering from the bar

• A single checker on a point is called a blot. If one of your checkers lands on your opponent's blot, the blot is hit and goes onto the bar. One checker can hit several blots in one turn by stopping on each of them.
• If you have any checkers on the bar, you must bring them back into play (enter them) before you move any other checker. A checker enters in your opponent's home board, on the point matching the number rolled. A 1 enters on your 24-point, a 2 on your 23-point, and so on up to a 6 on your 19-point. The point must be open.
• If neither number lets you enter, you lose the whole turn. If you have several checkers on the bar, you enter as many as you can and lose the rest of the turn. Once all your checkers are back on the board, you play any unused numbers as usual, with the checker that just entered or with any other checker.

5. Bearing off

• You can start bearing off only when all 15 of your checkers are in your home board.
• A roll lets you remove a checker from the point with the same number: a 6 removes a checker from your 6-point, a 3 from your 3-point, and so on.
• If no checker stands on the point of the number rolled, you must make a legal move with a checker on a higher-numbered point. If there are no checkers on higher points, you bear off a checker from your highest occupied point.
• You don't have to bear off if you can make another legal move. The rule to use as much of the roll as possible (section 3) still applies.
• If one of your checkers is hit while you are bearing off, you must enter it and bring it back to your home board before you can bear off again.
• The first player to bear off all 15 checkers wins the game.

6. Winning a game and scoring

A game is worth one point to start with. The winner scores that value multiplied by the value of the doubling cube (section 7):

• Gammons and backgammons count whether or not the cube has been turned. The Jacoby rule, sometimes used in money play, does not apply to matches.
• A game is played to the end unless a player passes a double (section 7) or resigns.
• A game cannot be cancelled, replayed or ended by agreement.
• A player who cannot win may resign the game. A resigned game counts as a single game, gammon or backgammon, depending on the position.

7. The doubling cube

The doubling cube has the numbers 2, 4, 8, 16, 32 and 64 on its faces and shows the current value of the game. Every game starts with the cube in the middle, at a value of 1, and either player may use it.

• Offering a double. At the start of your turn, before you roll, you may offer to double the value of the game. You cannot double on the opening move.
• Taking. If your opponent accepts (takes) the double, play continues at twice the value. Your opponent now owns the cube, and only they can offer the next double.
• Passing. If your opponent refuses (passes or drops), the game ends at once. They lose the value the game had before the double: 1 point if the cube was in the middle, or the current cube value after a redouble.
• Redoubles. The owner of the cube may redouble at the start of any of their own turns, before rolling. After a take, ownership passes to the player who took. The cube goes up to 64.

8. Match play and the Crawford rule

• Tournament matches are played to a set number of points, usually an odd number. In the app, tournaments are played to a length set by the organiser — 3, 5, 7, 9, 11, 13 or 15 points, or single games of 1 point. Each game won adds its points (section 6) to the winner's score. The first player to reach the match length wins the match. Points scored beyond the match length make no difference.
• Crawford rule. The first time either player comes within one point of winning the match, the next game is played without the doubling cube, unless the tournament conditions say otherwise. This is the Crawford game. From the game after it, either player may double again as usual.
• A match is won when a player reaches the match length, or when the opponent resigns the match, forfeits it or runs out of time.
• Match result for tournament standings: a win counts 1 point and a loss 0. A match forfeited without play is recorded as “+” for the winner and “−” for the loser.

9. Playing online in the app

In the app, the server takes care of the dice, the clock and the score, so the over-the-board procedures in section 11 do not apply. The following rules apply instead:

• Dice and moves. Dice are rolled by our servers, and every move is recorded. The app accepts only legal moves. When there is no legal move, or only one way to play a roll, the app may play it for you. The server records are the reference for the moves and the result of every match.
• Turn timer and time bank. Each turn has a short turn timer. When it runs out, your time bank starts to count down. The time bank belongs to the whole match: it is not refilled between games. The turn timer and time bank depend on the game speed or the tournament conditions.
• Running out of time. If your turn timer and time bank both run out while you still have a legal move, you lose the match, and your opponent is given the points they need to win it.
• Answering a double. When your opponent doubles, you have a short time to take or pass, and then your time bank is used. If both run out, the double counts as passed.
• Disconnection. If you lose connection, your time keeps running. Reconnect as soon as you can. If you don't return before your time runs out, you lose the match. Some time bank used while you were disconnected may be given back, a limited number of times per match. Some tournaments also have an inactivity limit. If it's your turn and you stay disconnected, or keep the app in the background, for longer than that limit, you lose the current game.
• Resigning. You can resign the current game. It is scored from the position on the board — single game, gammon or backgammon — times the cube value. Where the app offers it, you can also resign the whole match. Your opponent is then given the points they need to win it.
• Fair play. You may not use bots, analysis software or anyone else's help during a match, play on another player's account, or fix results (see Terms of Use, section 5). If you believe a result is wrong, contact support@i-bg-federation.com within 7 days of the match (Terms of Use, section 4).

10. Tournament formats

The organiser chooses the format of each tournament and shows it on the tournament's Details tab. Common formats are:

• Round robin. Every player plays every other player once or more. Large fields may be split into groups first.
• Swiss system. A set number of rounds. In each round, players with the same score, or the nearest score, are paired against each other, and no two players meet twice. If there is an odd number of players, one player gets a bye, which counts as a win without play.
• Swiss with elimination. A Swiss system in which a player is eliminated after a set number of match losses. Play continues until one player remains. The others are ranked by the round in which they were eliminated, then by number of wins.
• Knockout (single elimination). The loser of each match is out. Players are drawn into a bracket once, before round 1. If the number of players is not a power of two (8, 16, 32 …), some players receive a bye into round 2. A match for third place between the two losing semi-finalists may be played.
• Double elimination. Everyone starts in the winners' bracket. A player who loses once moves to the losers' bracket, and a player who loses twice is out. The winners of the two brackets meet in the final. The tournament conditions say whether an extra match is played if the winners'-bracket player loses the final.
• Knockout with re-entry. Where the conditions allow it, a player who loses early may re-enter the same bracket and fill a vacant first-round place.
• Mixed systems. Different systems are used at different stages, for example groups followed by a knockout.

Standings and tie-breaks. In round-robin and Swiss events, players are ranked by the number of matches won. Equal scores are separated by tie-break criteria in the order set by the tournament conditions: tie-break coefficients, number of wins, results between the tied players, and results against the higher-placed players.

Withdrawal. If a player withdraws from a round-robin event after playing fewer than half of their matches, their results are left out of the final standings. If they played half or more, their results stand and their unplayed matches count as losses. In knockout and Swiss events, a player who withdraws is eliminated, and the results of matches already played stand. Players found to have fixed a match are disqualified, and their results in the event are annulled as far as possible.

11. Over-the-board play

At live events played on a physical board, the following rules also apply, unless the event regulations say otherwise. Judges supervise play. Their decisions must be followed, and they can be appealed as described below.

Before the match

• Take your seat at least 5 minutes before the round starts. Use that time to check the checkers, the clock setting and the dice, and to fill in the match sheet.
• Seats, playing direction and colours are decided by each player rolling one die. The higher number chooses. A player who arrives after the start of the round loses this choice.
• The round starts on time. If you are late, your clock is started. If you arrive before your time runs out, you play on with the time left. If you don't arrive before your time runs out, you lose the match.

Clocks and time control

• Matches are played with a two-sided game clock. The time control is set by the event regulations. A typical control gives each player 2 minutes per match point plus a delay of 5–45 seconds on every move. Blitz controls are 30 seconds (1-point match), 1 minute (3 points), 2 minutes (5 points) or 3 minutes (7 points), each with an 8–12 second delay per move. In matches of 7 points or more, each player gets an extra 5 minutes unless breaks are scheduled.
• The delay is spent first on each move, before your main time starts to run. Unused delay is not carried over.
• Your turn is complete when you press your clock. Press it with the same hand you moved with, and never before you have moved. Do not keep your hand on or over the clock button.
• You are responsible for your own time. Only your opponent may remind you to press your clock, and only you, your opponent or a judge may point out that time has run out. If your time runs out, you lose the match. Complaints about the clock must be made before time runs out.
• Stopping the clock counts as resigning the match, except when you stop it for up to 30 seconds to set up the next game, to recover dice that fell off the table, or to call a judge. If a judge decides you stopped the clock by accident, you get a caution instead.

Dice and rolling

• Play with the dice supplied by the organiser, rolled through a dice tower (baffle box) or from a cup, as the event regulations require. Each player may ask the chief judge to replace the dice once per match, between games. A player who changes or rejects a die without asking the chief judge gets a penalty point.
• When using a cup, shake the dice firmly at least three times and roll both together onto the board so that they roll and bounce freely. Do not throw them from your hand or lower them below the table.
• The dice must land flat in the right-hand section of the board. Roll again if a die lands outside it, lands on a checker or is not lying flat (cocked). If a die is balanced on an edge or stuck in the dice tower, either player may count three seconds aloud. If it hasn't settled by then, the roll is void and must be repeated. Nobody may shake the table or blow on the dice during the count.
• Don't pick up or roll your dice until your opponent has finished their turn and pressed the clock. If you roll too early, your opponent decides whether that roll stands.
• Don't touch the dice or the dice tower while your opponent is rolling. If you interfere with a roll, your opponent may choose any legal roll to play instead.

Moving the checkers and using the cube

• Move your checkers clearly, with one hand. Don't touch any checkers during your opponent's turn. Keep borne-off checkers off the playing surface until the end of the game.
• To double, turn the cube to the next value before you roll. Once you have picked up the cube, you must double. To take, place the cube on your side of the board, showing the value offered. To pass, say “pass” and stop the clock. A cube offered too early stays offered, and your opponent may finish their move first.
• The cube must stay in view at all times. It comes off the board only for the Crawford game. If there is a dispute, the position and value of the cube decide.

Illegal moves and setup errors

• If your opponent makes an illegal move, you may accept it or require it to be corrected. You must do this before you roll or turn the cube. Once you roll or double, the move stands. If your opponent has already pressed the clock, you may switch it back so that the correction is made on their time.
• Making illegal moves on purpose to gain time is a serious breach of the rules.
• An illegal move that neither player noticed cannot be changed later. No claims are accepted after a game has ended.
• If the starting position or the number of checkers is found to be wrong before both players have made two moves, the game is restarted from the correct position. Otherwise, play continues.

Breaks

Where the event regulations allow breaks, each player may take one break in a match to 7 or 9 points, two in a match to 11 or 13 points, and three in a match to 15 points or more. There are no breaks in matches of 5 points or less or in blitz. A break lasts at most 5 minutes and may only be taken between games. Taking an unauthorised break leads to a warning, and a second offence loses the match.

Conduct

Players must behave respectfully towards their opponents, judges, officials and spectators, and follow the judges' decisions. During play you must not:

• talk to anyone other than a judge about the game, or ask for or accept advice;
• use notes, books, tables or any electronic device (phone, tablet, computer, headphones, smartwatch) in the playing area, unless the chief judge allows it. You may only write down the score;
• leave the board on your turn, or leave the playing area, without a judge's permission;
• distract or disturb your opponent or other players, or analyse games in the playing hall;
• take back a move after you have pressed the clock;
• eat at the table. A closed bottle of water of up to 0.5 litres is allowed.

Results

The winner of each game records the score on the match sheet, and the loser checks it. At the end of the match both players sign the sheet, and the winner hands it to the judge. A mistake on the sheet can be corrected until either player finishes the next game or turns the cube in it.

Penalties

Depending on how serious the breach is, a judge may give a caution, a warning, a penalty point, or award the loss of the game. The judges' panel may exclude a player from the event. As a rule:

• a first minor breach earns a caution, and a first serious breach earns a warning;
• a repeated breach in the same game, or a breach that directly affects the game, loses the game;
• repeated breaches in later games, deliberate systematic breaches, or a deliberate breach after an earlier penalty can lead to exclusion;
• deliberately losing, fixing matches or other cheating leads to exclusion and may lead to disqualification.

Judges and appeals

You may stop the clock and call a judge about any question on the rules. If you disagree with a match judge's decision, you may ask the chief judge or a deputy to review it. A decision of the chief judge may be appealed to the event's appeals committee.

12. Glossary

Questions about these rules or about a match played in the app: support@i-bg-federation.com. For fair-play rules and result disputes, see our Terms of Use.